Abstract: An apparatus for accurately measuring laser beam intensity profiles so as to permit adjusting the oscillation mode of the laser to achieve good workability of the beam. The beam from a CO.sub.2 laser generator is attenuated and applied to an infrared sensor which produces an electrical analog signal representing the beam intensity. The sensed signal is amplified and applied via an A/D converter and an interface to a computer. The computer controls a scanner which scans successive scanning lines of the laser beam profile across the sensor. The computer also produces a visual image of the laser beam intensity profile from the sensor signal. An operator veiwing such image can make an accurate and convenient measurement of the laser beam intensity profile, thereby providing a basis for quantitative analysis in quality inspection of workpieces subjected to the laser beam.